Molecular confirmation of pathological specimen integrity in Australasia

Sonic Clinical Institute, Douglass Hanly Moir Pathology, Sydney, NSW, Australia.
Pathology (Impact Factor: 2.19). 05/2009; 41(3):280-3. DOI: 10.1080/00313020902756311
Source: PubMed


Investigations into 14 suspected pathology sample identification errors and mix-ups were performed, as a service for several public hospital and private laboratories, from 2005 to 2007.
Analyses were performed with the forensic ABI Identifiler kit of 16 microsatellites (15 autosomal and amelogenin) on DNA from paraffin-embedded tissues or blood specimens and compared to independently verified (single or multiple) patient samples.
Of 23 unique patient specimens referred for sample integrity confirmation because of pathologist, clinician or patient concern, six (26.1%) were demonstrated to be discordant, indicating that specimen identification errors or mix-ups had occurred.
Due to their great sensitivity and high discrimination power, forensic identity multiplex systems using either microsatellites or single nucleotide polymorphisms (SNPs) can resolve concerns about pathology specimen identity and integrity.

Download full-text


Available from: Christopher G Bell, Sep 29, 2014
13 Reads
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: During specimen processing in surgical pathology laboratories, specimen-related adverse events (SRAEs), such as mislabeling and specimen mixed-up might occur. In these situations, molecular techniques using short tandem repeat (STR) loci are required to identify the personal identity. Microsatellite instability (MSI) test is widely used for screening the hereditary non-polyposis colon cancer (Lynch syndrome) in surgical pathologies using polymorphic STR markers. We tried to evaluate the applicability of the MSI test for SRAEs. We obtained 253 MSI test results to analyze the allele frequencies. After calibrating the estimated nucleotide lengths, we calculated the allele frequencies, a random match probability, and a likelihood ratio (LR) of three dinucleotide STR markers (D5S349, D17S250, and D2S123). The distribution of LR was 136.38 to 5,606,213.10. There was no case of LR<100. In addition, there were 153 cases (60.5%) of LR ranging from 100 to 10,000 and 100 cases (39.5%) of LR>10,000. Furthermore, the combined probability of identity was 9.23×10(-4) and the combined power of exclusion was 0.99908. Using the three STR markers that are recommended for MSI test, all the cases were positively identified in 1% range and about one-third cases showed high LR (>10,000). These results showed that MSI tests are useful to screen the personal identity in case of SRAE in pathology laboratories.
    04/2012; 46(2):131-6. DOI:10.4132/KoreanJPathol.2012.46.2.131
  • [Show abstract] [Hide abstract]
    ABSTRACT: Background: The diagnostic algorithm for most cancers includes the assessment of a tissue specimen by a surgical pathologist, but if specimen provenance is uncertain, the diagnostic and therapeutic process carries significant risk to the patient. Over the last decade, short tandem repeat (STR) analysis has emerged as a DNA-based method with clinical applicability for specimen identity testing (also known as specimen provenance testing). Although the clinical utility of identity testing using STR-based analysis has been demonstrated in many studies, its economic value has not been established. Methods: We developed a decision-analytic model of the application of STR-based provenance testing of transrectal prostate biopsy specimens obtained as part of routine clinical care to rule out the presence of adenocarcinoma of the prostate, as compared with no STR-based testing. Using parameter values drawn from the published literature, the cost-effectiveness of STR-based testing was quantified by calculating the incremental cost-effectiveness ratio per quality-adjusted life-year gained. Results: In comparison to the current standard practice of no identity testing, identity testing by STR-based analysis has an incremental cost-effectiveness ratio of $65,570 per quality-adjusted life-year gained at a testing cost of $618 per person. At a cost of $515 per person, identity testing would meet the conservative standard of $50,000 per quality-adjusted life-year. At a test cost of $290 per person, identity testing would be cost saving. Conclusion: Given the rapidly declining pricing of STR-based identity testing, it is likely that testing to confirm the identity of positive prostate biopsy samples will be a cost-effective method for preventing treatment errors stemming from misidentification. Studies to formally establish the frequency of specimen provenance errors in routine clinical practice would therefore seem justified.
    Value in Health 09/2012; 15(6):860-7. DOI:10.1016/j.jval.2012.04.011 · 3.28 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Occult specimen provenance complications (SPCs), which occur when there is an absence of any direct or indirect indication that a specimen switch or contamination may have occurred, constitute a significant patient safety and medical-legal problem because they can lead to misdiagnosis. However, the rate at which occult SPCs occur is unknown because, by definition, this category of errors is not identified by standard laboratory practices. In this study, we evaluated a data set comprising almost 13,000 prostate biopsies that were prospectively tested for specimen provenance errors as part of routine clinical practice. The frequency of occult type 1 errors (a complete transposition between patients) and type 2 errors (contamination of the patient's tissue with 1 or more unrelated patients) was 0.26% and 0.67%, respectively; every urology practice setting and surgical pathology laboratory type with a representative sample size experienced at least 1 type 1 and 1 type 2 error during the study period. Overall, the mean frequency of SPCs across practice settings was 0.22% for type 1 errors and 1.69% for type 2 errors. The type 1 rate showed no correlation with a surgical pathology laboratory setting or urologic practice group setting; the type 2 rate correlated solely with a surgical pathology laboratory setting. The occult SPC rate in this limited data set provides an estimate of the scope of the problem of potential misdiagnosis as a result of occult specimen provenance errors in routine clinical practice.
    American Journal of Clinical Pathology 01/2013; 139(1):93-100. DOI:10.1309/AJCP50WEZHWIFCIV · 2.51 Impact Factor
Show more